Leases - Future Minimum Payments Due Under Non‐Cancelable Leases - ASC 840 (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Future minimum payments due under Operating Leases:
2019	$ 38,057
2020	29,346
2021	22,239
2022	16,782
2023	12,302
Thereafter	18,874
Future minimum payments due under Finance Leases
2019	20,080
2020	11,851
2021	9,018
2022	4,169
2023	2,244
2024 and thereafter	3,617
Total minimum lease payments	50,979
Less: imputed interest	6,743
Total net minimum lease payments	44,236
Less: Current portion of obligations under finance leases	17,498
Long-term portion of obligations under finance leases	$ 26,738